i'd start by trying and watch one by every bond, i'll suggest some that will give you a good flavour of each bond as well as capturing a range of different bond experiences. then you can move based on what you like.
connery - goldfinger is kinda the quintessential bond film. good campy fun, great pacing, entertaining villain, good humour, excellent finale. i'd also reccomend from russia with love as a more grounded espionage story, rooted in fleming's books which gives connery more to work with.
lazenby - ohmss (obviously). i think watching this is good as not only is it great fun, every ski scene with the theme blasting is wonderful, but it shows a different romantic side to bond and lazenby plays that airy, charming side very well.
moore - the spy who loved me. the moore era was defined by ramping up the goofiness, the gadgetry and campy one liners. this one isn't my favourite but it's the best of the classic silly moore approach with its underwater car, jaws and is generally well paced and entertaining.
dalton - the living daylights. while dalton's bond is regularly praised for being darker and more interesting as a character than just an archetype, this is still a very fun bond film. loads of great set pieces, tons of locations, an amazing aircraft scene that probably inspired uncharted 3. it could be a moore film, yet dalton's performance lends it a very different tone.
brosnan - goldeneye. brosnan is a move away from the darker dalton, more to the sort of handsome, suave iconic feel yet this film has some interesting characterization thanks to the relationship between him and alec trevelyan, his old friend and partner who turns bad. the rest of the film is fairly standard, though with good action, but sean bean really elevates it.
craig - casino royale. redefined bond for the modern era, combining brilliant action bombast, tragic love and tense thriller elements into a great bond film. craig's bond is very physical, brutal and kinda darkly funny and ties the whole big film all together with his presence.